"Am I killing something?" -Obvious sign of casual sadism, common in an assassin.

"A necromancer? Lame!" -Necromancers are more boring than they look. All they do is chant and play around with candles. Since Gabry actually knows this, it seems he's had experience with them before. And since it's unlikely that a person would be hired to kill one necromancer (let alone two), it seems that they are involved in some specific type of crime organization.

That's a little alarming. Hmm…I wonder how often his targets are monsters compared to humans. Also if he feels bad for anything he kills or if he sees them all as the same. Unrelated, he looks really good in the 5th panel.